Effect of deposition method and the surfactant on high capacitance of electrochemically deposited MnO_2 on stainless steel substrate

摘要

Manganese dioxide has been considered as a promising material for electrochemical supercapacitors. In order to obtain a high specific capacitance, MnO_2 has been electrodeposited from an aqueous acidic solution of MnSO_4 consisting of an ionic surfactant, namely, sodium lauryl sulphate (SLS) on stainless steel. The electrodeposited films of MnO_2 in the presence of the surfactant possess greater porosity and hence greater surface area in relation to the films prepared in the absence of the surfactant. Cyclic voltammetry and galvanostatic charge–discharge cycling experiments reveal that specific capacitance is higher by about 22% due to the effect of SLS.